Users have access to a wide range of content in an ever increasing variety of ways. Wide availability of content, such as software and digital media, and easy access to the content through the Internet has resulted in unintended and unauthorized use of the content. Digital Rights Management (DRM) may be employed to manage rights for content from creation to consumption, and may protect digital content from illegal accesses or copying. Most DRM systems are based on encryption in which the content is encrypted and distributed. Traditionally, a consumer who wants to output the encrypted content must first get permission to access the content and get a decryption key for the encrypted content, which may be provided in the form of an encrypted license. The DRM system enforces the proper usage of the digital content through use of the encrypted license.
In a conventional DRM system, license acquisition requests are processed by a centralized license server. This makes the centralized license server heavy-loaded, complex, and expensive to run and maintain, and makes it a weak link in the DRM system. For example, failure of the centralized license server may disrupt normal DRM services. Additionally, small content providers, such as a peer in a peer-to-peer network, may not be able to afford the cost of providing and/or utilizing the services of the centralized license server.
Peer-to-peer networks have recently attracted increased attention in both academia and business. Peer-to-peer networks offer many desirable features, such as adaptation, self-organization, load-balancing, fault-tolerance, low cost, high availability, scalability, and may be configured to provide a large pool of resources. Peer-to-peer networks have emerged as a popular way to share large amounts of data, such as by peers downloading songs that are referenced as being available for download through a peer-to-peer website. Most peer-to-peer networks, however, do not have digital rights management or access control. Consequently, peer-to-peer networks can be liable for contributing to the infringement of the copyright in works that are referenced as being available for download by the peer-to-peer networks.
Accordingly, there is a continuing need for a distributed public licensing infrastructure for digital rights management systems.